Housing for a coolant fluid pump

Abstract

The invention relates to a housing for a coolant fluid pump (2), in particular for a coolant fluid pump of an immersion cooling circuit, comprising a drive housing (3), a cover (4) and a pump housing (5), wherein the drive housing (3) is axially covered on one side by the cover (4) and is positioned axially opposite the cover (4) of the pump housing (5), wherein the drive housing (3) is connected to the pump housing (5) and the drive housing (3) is connected to the cover (4) in a gap-free, materially bonded manner, i.e. by means of a gap-free, materially bonded connection.

Description

[0001] The invention relates to a housing for a coolant fluid pump according to the preamble of claim 1.

[0002] Common housings for coolant fluid pumps have a drive housing that contains at least most of the components that make up the electric drive of the coolant fluid pump. Furthermore, the drive housing is usually closed at one end with a cover. At the axially opposite end of the cover is typically a pump housing containing a fluid pump that can be driven by the electric motor. The fluid pump can be of various designs, for example, a centrifugal pump, a gerotor pump, or a similarly suitable type.

[0003] A drive shaft of an electric motor, which is located in the drive housing, engages in the pump housing and interacts mechanically with a pump element, for example a pump impeller.

[0004] The housing components of such pumps are typically screwed, clamped, clipped, or similarly joined together. Depending on the intended use of such a fluid pump, seals may be provided between the housing components or between the internal chambers and the external environment.

[0005] This type of design is relatively cumbersome to assemble, especially when seals are required. Furthermore, it necessitates a large number of individual parts. Moreover, such designs are often limited in terms of the variability of possible assembly positions for the individual components relative to each other. This means, for example, that the rotational position of the pump housing or the end cap relative to the drive housing is either fixed or must be achieved in fixed iterative steps. A stepless, arbitrary arrangement in a circumferential direction is often not possible. In addition, such fluid pumps are not always satisfactory, particularly with regard to their EMC (electromagnetic compatibility) properties and the assurance of adequate ESD (electrostatic discharge) properties.

[0006] The object of the invention is therefore to provide a housing for a fluid pump, in particular a housing for a fluid pump for immersion cooling circuits, which avoids or at least significantly mitigates the aforementioned disadvantages of the prior art. In particular, electrostatic discharge properties as well as a high degree of electromagnetic compatibility are important for fluid pumps in immersion cooling circuits, since an immersion cooling circuit is characterized by the fact that the cooling fluid used is an insulating, i.e., electrically non-conductive fluid, and electrostatic charges can occur, in particular, due to the circulation of such a cooling fluid. Such electrostatic charges can potentially cause damage to the components to be cooled, which are often batteries, when such a cooling fluid is circulated.

[0007] A housing according to the invention, in particular for a coolant fluid pump of an immersion cooling circuit, has a drive housing, a cover and a pump housing, wherein the drive housing is axially covered on one side by the cover and the pump housing is set axially opposite the drive housing to the cover, wherein the drive housing is connected to the pump housing and the drive housing is connected to the cover in a gap-free, material-bonded manner, i.e. by means of a gap-free, material-bonded connection.

[0008] A gap-free, material-bonded connection of the housing components creates a continuous metallic, i.e., electrically conductive, housing across all connection points. "Gap-free" in the context of the invention means that opposing surfaces of the connection already touch, at least partially, before the connection is made, or have such a small gap that the practical requirements of welding, e.g., laser welding, are met. Specifically, this means a maximum gap of only a few tenths of a millimeter, e.g., a maximum of 2-3 tenths.

[0009] In an advantageous embodiment, the gap-free, material-bonded connection is adhesive-free and gas-tight.

[0010] To create a gap-free, material-bonded connection, it has proven effective to execute the gap-free, material-bonded connection as a continuous laser weld without a seal (i.e., without additional sealing components), i.e., as a laser sealing weld, or as a spot weld, particularly as a laser spot weld using an O-ring. An adhesive-free, material-bonded connection means that no adhesive is used to create the bond, but rather that this connection, possibly with the addition of filler material, is formed to a significant extent from the material of the housing components to be joined, e.g., by fusing.

[0011] With regard to the choice of materials, it is advantageous that the drive housing and / or the closure cover is made of a metallic wrought alloy and that the pump housing is designed as a die-cast part.

[0012] The preferred manufacturing method has been found to be that the drive housing and / or the closure cover is a cold-formed component, an extruded profile component, or that these components are manufactured by means of rheocasting.

[0013] With regard to the EMC behavior of a fluid pump manufactured with the pump housing according to the invention, it is particularly advantageous that the drive housing, the cover and the pump housing form a faradaic cage when connected together.

[0014] If the housing is electrically connected to a common ground connection of a motor electronics, a particularly simple, process-reliable, and especially maintenance-free common ground connection can be created for all conductive components of the pump housing (i.e., at least for the drive housing, the cover, and the pump housing).

[0015] Regarding the choice of materials for the components of the pump housing, it is also possible for the drive housing, the cover, and the pump housing to be made of a single plastic, particularly an electrically conductive plastic. Such a design is particularly suitable when there are less stringent requirements for heat dissipation via the pump housing components of the fluid pump.

[0016] To achieve electrical conductivity in a plastic used, it is advantageous to coat the drive housing and / or the closure cover and / or the pump housing, at least on their inner surfaces, with a conductive layer, for example painted, and to connect this electrically conductive layer to the ground connection of a motor electronics.

[0017] The invention will now be explained by way of example with reference to the drawing. The drawing shows: Fig. 1: a longitudinal section through a coolant fluid pump with a housing according to the invention; Fig. 2: an isometric view of a coolant fluid pump which has a housing according to the invention.

[0018] Fig. Figure 1 shows a housing 1 according to the invention, which is suitable for use in a coolant fluid pump 2, in particular a coolant fluid pump 2 of an inversion cooling circuit, in longitudinal section.

[0019] The essential components of the housing 1 are a drive housing 3, a cover 4 which axially covers the drive housing 3 at one end, and a pump housing 5 which is axially positioned opposite the cover 4 against the drive housing 3.

[0020] Inside the drive housing 3, an electric motor 7 with a stator 8 and a rotor 9 is arranged in its interior 6. A shaft 10 of the rotor 9 is guided axially and radially in a bearing arrangement 11 and is rotatably mounted in a circumferential direction U.

[0021] The electric motor 7 can optionally be designed as a wet-running electric motor or as a dry-running electric motor.

[0022] A cover 4 is arranged at a first axial end 12a of the drive housing 3, covering the interior 6 of the drive housing 3, with the cover 4 contacting the drive housing 3 in the area of ​​a first flange assembly 13. Motor electronics 15 are located on an inner surface 14 of the cover 4 and are electrically connected to the stator 8 of the electric motor 7 via suitable contact elements 16.

[0023] Furthermore, the closure cover 4 carries an electrical connection module 17, which is designed in a customer-specific manner and is electrically connected to the motor electronics 15 in the area of ​​the interior 6.

[0024] Flange surfaces of the first flange device 13 are designed as annular surfaces or as cylindrical surfaces or as cylindrical section surfaces, which are arranged rotationally symmetrically around an axis of rotation R of the shaft 10, in particular coaxially to the axis of rotation R, so that an arbitrary rotational positioning of the closure cover 4 relative to the drive housing 3 is possible in the circumferential direction U.

[0025] At least some contacting surfaces of the flange device 13 are connected to each other by means of a gap-free, material-bonded connection 18, in particular without adhesive, for example by means of a circumferential laser weld 18, which in a special embodiment is also gas-tight.

[0026] In this respect, the aforementioned freely oriented rotational positioning of the closure cover 4 relative to the drive housing 3 refers to a state prior to the formation of the material-bonded, and in particular gas-tight, connection, for example, the laser weld 18. Naturally, after the laser weld 18 has formed, freely oriented rotational positioning of the closure cover 4 relative to the drive housing 3 is no longer possible. The aforementioned freely oriented rotational positioning of two components, for example, the closure cover 4 relative to the drive housing 3, makes it possible to largely accommodate customer-specific requirements regarding the positioning of, for example, the electrical connection module 17, without modifications to the underlying components.

[0027] At a second axial end 12b of the drive housing 3, axially opposite the end cap 4, the pump housing 5 is positioned against the drive housing 3 by means of a second flange assembly 19. The contact surfaces of the second flange assembly 19 are also preferably circular surfaces, annular surfaces, cylindrical surfaces, or parts of cylindrical surfaces, which are arranged rotationally symmetrically around the axis of rotation R1, in particular coaxially to the axis of rotation R. This makes it possible, as in the area of ​​the first flange assembly 13 before the fixed connection of the pump housing 5 with the drive housing 3, to achieve any desired positioning of the pump housing 5 relative to the drive housing 3 in the circumferential direction U.The pump housing 5, which is designed, for example, as the pump housing 5 of a centrifugal pump or as the pump housing 5 of a gerotor pump, or more generally as the pump housing 5 of a fluid pump unit, has, for example, pump outlets (not shown) which, when the fluid pump is installed, are to point in a specific direction into a cooling circuit, for example, an immersion cooling circuit, according to customer specifications. Such customer requirements can be easily implemented without modifying any of the components involved by rotating the pump housing 5 in any circumferential direction U relative to the drive housing 3 before their material-fit connection.

[0028] In the area of ​​the second flange assembly 19, at least some of the opposing surfaces of the first flange assembly 19, in particular gap surfaces extending in a radial direction RA, are connected by means of a second metallurgical connection, for example a second continuous laser weld 18. Preferably, the laser weld 18 is designed as a continuous laser weld 18 to create a gas-tight connection between the pump housing 5 and the drive housing 3.

[0029] The drive housing 3, the cover 4, and the pump housing 5 are all made of metal, with the drive housing 3 and the cover 4, for example, being made of a wrought metal alloy, such as a wrought aluminum alloy. Due to its more complex basic geometry, the pump housing 5 is preferably made of die-cast aluminum.

[0030] The above-described formation of the gap-free, material-bonded connection enables, in particular, a simple, seal-free connection of the respective components, i.e., the closure cover 4 relative to the drive housing 3 or the pump housing 5 relative to the drive housing 3, since the laser welding is particularly gas-tight and circumferential, so that separate sealing components are not necessary.

[0031] However, the material-bonded connection, the prescribed laser welds 18, can also be interrupted in the circumferential direction U, which then necessitates the provision of sealing components, for example flat gaskets or O-ring seals.

[0032] Such an interrupted laser weld 18 can, for example, be a laser spot weld or a laser weld 18 with a plurality of laser weld beads of a certain length, each spaced apart from the others in the circumferential direction U.

[0033] It has proven particularly advantageous that the drive housing 3 and / or the closure cover 4 are each a cold-forged component or an extruded profile component or are manufactured by means of rheocasting.

[0034] In particular, the rheocasting manufacturing process offers special properties in the components produced in this way, which are especially advantageous for realizing the invention. Of particular note are the design objectives that can be achieved through the component properties attainable via rheocasting. Rheocasting is a type of die-casting process; however, the melt contains up to 35% solids.

[0035] The advantages mentioned include, for example: - Especially compared to die casting, the use of alloys with higher strength, thermal conductivity and the like is possible; - The components have a very low porosity, which reduces quality problems and allows for heat treatments and welding; - It is a cost-effective manufacturing process due to the possible use of smaller machines (on average -30% reduction in machine size compared to a corresponding die-casting production of the components); - Even larger differences in wall thickness within the component are not a problem; - Reduction of the die-casting machine size (i.e., lower mold opening forces), thus enabling smaller machines; this results in a more favorable machine hour rate; a higher number of mold cavities is possible for a given machine size when using a multi-cavity mold; - Laminar mold filling possible (in a standard die-casting process, mold filling is turbulent); - Due to the specific behavior of the metal slurry used in rheocasting, very thin ribs and webs can be cast; - Longer lifespan of the die-casting mold or reduced maintenance costs; - Use of special alloys which would be difficult or impossible to cast using normal die casting is possible; - High-quality castings can also be achieved using secondary alloys, thus contributing to a significantly improved CO2 balance.

[0036] The invention results in particularly noteworthy component properties as follows: - No additional leak test / pore analysis of the components is required; - Thick and thin wall thicknesses with relatively high transition gradients are possible; - By appropriately designing the die-casting mold, especially the venting, components that are almost free of pores and / or voids are possible; - The alloy can be chosen more freely and, if necessary, adapted to the welding process or welding equipment to be used; - In some cases, it may even be possible to forgo additional welding material.

[0037] As a result, the components closure cover 4, drive housing 3, and pump housing 5, after the formation of the particularly circumferential, gapless, metallurgical connection 18, form a one-piece metallic block that encloses the interior space 6, so that this interior space 6 is surrounded by a Faraday cage. Furthermore, the gapless design of the metallurgical connections significantly reduces or even prevents any antenna effect similar to that of a dipole antenna. Both measures are particularly advantageous with regard to the increasing requirements for electromagnetic compatibility (EMC) as well as with regard to increasing requirements concerning the static charge of the housing 1 according to the invention, or the reduction / prevention of any potential electrostatic charging. Thus, the invention also meets increasing requirements regarding ESD parameters.

[0038] Furthermore, it is advantageous that the entire housing 1 of the fluid pump 2, consisting at least of the components pump housing 5, drive housing 3 and end cap 4, acts electrically as a single component, since the individual parts have a materially bonded, permanently electrically conductive connection to each other, so that the entire housing 1 can be connected to a corresponding external ground and / or a ground connection 21 of the motor electronics 15 by means of a single common ground connection 20.

[0039] As an alternative to the prescribed embodiment in which the components drive housing 3, end cap 4, and pump housing 5 are made of metal, it is also possible for these components to be made of an electrically conductive plastic and for the bonded, gap-free connection 18 to be made by ultrasonic welding or friction welding. To achieve electrical conductivity in a plastic, it is possible, for example, to coat the inner surfaces of the components pump housing 5, drive housing 3, and end cap 4 with an electrically conductive lacquer.

[0040] Fig. Figure 2 shows an isometric external view of a housing 1 of a fluid pump 2 according to the invention, wherein a continuous line 30 between the drive housing 3 and the closure cover 4 and a continuous line 31 between the drive housing 3 and the pump housing 5 are intended to graphically represent the continuous, material-bonded, gap-free connections 18, for example the laser welds 18 mentioned above.

[0041] The in Fig. The two material-bonded connections 18 shown are formed as continuous laser welds 18. As an alternative to laser welds 18, friction stir welding can also be used for the gap-free, material-bonded connections 18 of the components drive housing 3, closure cover 4 and pump housing 5. Reference symbol list 1 case 2 Coolant fluid pump 3 drive housings 4 sealing caps 5 Pump housings 6 Interior 7 Electric motor 8 Stator 9 Rotor 10 wave 11 Storage arrangement 12a first axial end 12b second axial end 13 first flange assembly 14 Inside 15 Engine electronics 16 contact elements 17 Connection module 18. Gapless, material-bonded connection; laser welding 19 second flange device 20 external ground connection 21 Ground connection of the motor electronics 30 / 31 continuous lines R axis of rotation U circumferential direction RA Radial direction

Claims

Housing for a coolant fluid pump (2), in particular for a coolant fluid pump (2) of an immersion cooling circuit, comprising a drive housing (3), a cover (4) and a pump housing (5), wherein the drive housing (3) is axially covered on one side by the cover (4) and the pump housing (5) is positioned axially opposite the drive housing (3) to the cover (4), characterized in that the drive housing (3) is connected to the pump housing (5) and the drive housing (3) is connected to the cover (4) in a gap-free, materially bonded manner, i.e. by means of a gap-free, materially bonded connection (18). Housing according to claim 1, characterized in that the gap-free, materially bonded connection (18) is gas-tight. Housing according to claim 1 or 2, characterized in that the gap-free material-jointed connection (18) is designed as a seal-free, i.e. without additional sealing components, continuous laser weld (18), i.e. as a laser sealing weld or as a spot weld, in particular as a laser spot weld using a sealing component, for example an O-ring. Housing according to one of the preceding claims, characterized in that the drive housing (3) and / or the closure cover (4) is made of a metallic wrought alloy and the pump housing (5) is designed as a die-cast part. Housing according to one of the preceding claims, characterized in that the drive housing (3) and / or the closure cover (4) is a cold-extruded component, an extruded profile component or is manufactured by rheocasting. Housing according to one of the preceding claims, characterized in that the drive housing (3), the closure cover (4) and the pump housing (5) form a faradaic cage when connected together. Housing according to one of the preceding claims, characterized in that the drive housing (3), the closure cover (4) and the pump housing (5) are electrically connected to a common external ground connection (20) or a ground connection (21) of a motor electronics (15). Housing according to one of claims 1, 2, 3, 6 and / or 7, characterized in that the drive housing (3), the closure cover (4) and the pump housing (5) are made of a plastic, in particular an electrically conductive plastic. Housing according to claim 7, characterized in that, in order to produce the electrical conductivity of a plastic used, the drive housing (3) and / or the closure cover (4) and / or the pump housing (5) are coated at least on their inner surfaces (14) with an electrically conductive layer, for example painted with an electrically conductive lacquer layer, and this electrically conductive layer is connected to the external ground connection (20) or the ground connection (21) of a motor electronics (15).

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